Treatment of T-cell mediated diseases

Abstract

The invention provides a method of treating T-cell mediated diseases and a method of inhibiting the activation of T-cells using certain diketopiperazines. The invention also provides methods of synthesizing diketopiperazines and pharmaceutical compositions comprising certain diketopiperazines. The invention further provides methods of making improved pharmaceutical compositions of proteins and peptides by either increasing or decreasing the content of diketopiperazines in the compositions and the resultant improved pharmaceutical compositions.

We claim: 
     
       1. A pharmaceutical composition comprising a diketopiperazine (DKP)-containing fraction of a solution of human albumin, wherein the DKP-containing fraction is produced by separating human albumin from the human albumin solution, wherein the DKP is DA-DKP, and wherein the composition further comprises about 0.01% of the albumin in a commercially available albumin pharmaceutical composition and a component selected from the group consisting of caprylic acid, N-acetyl tryptophan and combinations thereof and is an isotonic aqueous solution. 
     
     
       2. The composition of  claim 1  wherein the DKP-containing fraction contains components having molecular weights less than 3000. 
     
     
       3. The composition of  claim 1 , wherein the DKP-containing fraction is separated from the solution of the protein or peptide by a separation method selected from the group consisting of size exclusion chromatography, affinity chromatography, anion exchange chromatography, cation exchange chromatography and filtration. 
     
     
       4. A DKP-containing fraction produced by separating human albumin from a solution of human albumin, wherein the DKP is DA-DKP, and wherein the fraction further comprises about 0.01% of the albumin in a commercially available albumin pharmaceutical composition and a component selected from the group consisting of caprylic acid, N-acetyl tryptophan and combinations thereof and is an isotonic aqueous solution. 
     
     
       5. The DKP-containing fraction of  claim 4  wherein the fraction contains components having molecular weights less than 3000. 
     
     
       6. The DKP-containing fraction of  claim 5 , wherein the protein or peptide is separated from the solution of the protein or peptide by a separation method selected from the group consisting of size exclusion chromatography, affinity chromatography, anion exchange chromatography, cation exchange chromatography and filtration.